Python binary converter problem

Question

im having trouble with this code:

con_input  = input("1.binary-decimal 2.binary-ASCII 3.binary-hexadecimal\n-\n4.decimal-binary 5.ASCII-binary 6.hexadecimal-binary\n> ")




 if con_input != "1" and con_input != "2" and con_input != "3" and con_input != "4" and con_input != "5" and con_input != "6":
     print("enter one of the numerical options")


 def code_conversion():
     if con_input == "1":
         print("separate bytes by a space")
         binary_input = input("enter binary:\n> ")
         int(binary_input)
         while len(binary_input) < 8:
             print("please enter a 8bits or higher")
             binary_input = input("enter binary:\n> ")
         while "1" not in binary_input and "0" not in binary_input:
             error = ("Please enter binary")
             print("\nseparate bytes by a space")
             binary_input = input("enter binary:\n> ")
         binary_input = list(binary_input)
         if [0] in binary_input == '1':
             binary_input[0] = '128'
         print(binary_input)           

 code_conversion()

im trying to turn items in the list into their binary to decimal coversion depending if they are a 0 or a 1 however when I try it it does not seem to change to the 128 it just stays as the 1.

any help with this would be greatly appreciated

Answer 1 · 2015-03-11T05:47:32Z

March 11, 2015 5:47am

Thanks for reformatting your code. There is still an extra space preceeding lines in the bottom part of your code. But let's move on....

Looking at the function code_conversion(), I've added comments to your code trying to figure out your intentions:

def code_conversion():
    if con_input == "1":
        # convert binary to decimal
        print("separate bytes by a space")
        binary_input = input("enter binary:\n> ")
        # use int() to check for non-numbers
        int(binary_input)
        # loop until input has length 8 or more
        while len(binary_input) < 8:
            print("please enter a 8bits or higher")
            binary_input = input("enter binary:\n> ")
        # loop until input contains either a "1" or a "0"
        while "1" not in binary_input and "0" not in binary_input:
            error = ("Please enter binary")
            print("\nseparate bytes by a space")
            binary_input = input("enter binary:\n> ")
        # convert binary_input to list
        binary_input = list(binary_input)
        # if "list with 0 as element" is in boolean value from expression "binary_input == '1'"
        # this can't be what you want
        if [0] in binary_input == '1':
            # replace first character with string '128'
            binary_input[0] = '128'
        # print binary_input
        print(binary_input)

for the last if block, perhaps you meant:

        # if first element is '1', replace with '128'
        if binary_input[0] == '1':
            # replace first character with string '128'
            binary_input[0] = '128'

I would rethink two parts of your code.

First, during checking of the user input binary_input, the separate sections are not cummulative. That is, at each point the user could enter different code that passes one check but fails previous checks. Look at the following input I ran in ipython:

In [39]: code_conversion()
separate bytes by a space
enter binary:
> 0
please enter a 8bits or higher
enter binary:
> aaaaaaaaa

separate bytes by a space
enter binary:
> 1aaa
['128', 'a', 'a', 'a']

I changed my input and got through with non-binary data. Input checkout should be in one loop:

# import regexp  module
import re

while True:
    basic_input = input("> ")
    # check input length > or = 8, and
    # using re, check input contains only "1", "0", space
    if len(basic_input) >= 8 and re.search(r'^[10 ]*$', basic_input):
        print(basic_input)
        break

The other part to consider is the length of binary_input. If over 8 characters, then the first item binary_input[0] might have a value more than 128

Answer 2 · 2015-03-10T20:11:07Z

March 10, 2015 8:11pm

that should work :)

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Python binary converter problem

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